Water Resources Conditions and Possible Savings in Irrigation Systems Prof Wim Bastiaanssen

Which tools are available to assist planning ? Cheema – Ph.D. student TU-Delft Remote sensing Water basin models Groundwater flow models Climate models Water accounting GIS data Smart phone SMS messages Yesterday

Models are Required for Future Projection PAST FUTURE FUTURE: C FUTURE: A Policies: A, B, C Policies: A, B, C Observations Remote Sensing Simulation Models FUTURE: B Yesterday

Cheema – Ph.D. student TU-Delft Conclusions day 1 The basic data needed for planning is obsolete. Tools can assist with the derivation of real time and localized data The impact of certain interventions need to be understood, i.e. scenario analysis Water resources planning is a political process More attention should be given to convert information into evidence based decision making: data alone is not sufficient

From information to planning Data database Ministries & Agencies Targets Define Scenarios Tools Impact & Advice Parlement decisions (Technical component only)

Fluctuation of the renewable water resources ? Cheema – Ph.D. student TU-Delft Yearly Rainfall TRMM Satellite 1998 to 2012

RainfMM validation over Pakistan Rainfall trend 1998 to 2012 Cheema – Ph.D. student TU-Delft

Actual evapotranspiration Abyan

Modelling Recharge and Runoff for period (SPHY model) This are the renewable water resources

Cheema – Ph.D. student TU-Delft Integrate satellite data and ground stations Downscale and calibrate local rainfall (250 m) Compute actual evapotranspiration (250 m) Validate evapotranspiration where feasible Make water accounts for each basin Assess renewable water resources Determine degree of over-exploitation How to improve the knowledge on renewable water recourses ?

Water accounting

Can we reduce the water demand for irrigation ? Cheema – Ph.D. student TU-Delft Reduce abstractions of groundwater -Quota on water use, well licenses, stop subsidized diesel for pumps -Reduce crop ET by improved irrigation technologies -Reuse urban, industrial and irrigation water Control agricultural areas -Control irrigated area (ha) -Control cropping intensity -Abandon certain crops -Land retirement Enhance rainfed agriculture -New seeds -Better practices ……

Cheema – Ph.D. student TU-Delft irrigation efficiency improvement needs special attention

TRMM validation over Pakistan Irrigation efficiency of 40 % Net withdrawal is 1000 – 750 = 250 mm

TRMM validation over Pakistan Irrigation efficiency of 80 % Net withdrawal is 1000 – 350 = 650 mm, incremental ET is 400 mm Control your ET !

How to reduce crop evapotranspiration (ET) ? Cheema – Ph.D. student TU-Delft Use drought tolerant crop varieties Short duration crop varieties Apply mulching of row crops and tree crops Manage soil moisture within a preferred regime Introduce drip systems that reduced soil evaporation Apply a certain level of deficit irrigation that does not affect crop production

Cheema – Ph.D. student TU-Delft Crop water stress will not necessarily reduce production

Large variability of Qat ET in Rada

Impose a certain level of water stress Cheema – Ph.D. student TU-Delft Actual ET Potential ET Water stress

For every water basin: Improve the knowledge of renewable water resources, and the intra-annual fluctuations Assess the level of over-exploitation and estimate the reduction need Reduce irrigation water demand by ET reduction measures (mm) and areal control (ha) Focus on areas where recharge fulfills > 100 mm/yr Make water accounts current & future Define scenario’s and interventions Evaluate impact of scenario’s Advice Members of Parlement

Thank you !